Seized screw underwater and remote withdrawal device for nuclear reactor i.e. pressurized water nuclear reactor, in industrial facility, has extraction tool for extracting nets from tapping by anti-clockwise rotation of tool

摘要

The device has separating units for separating a support head of a barrel (30) of a seized screw for withdrawal of an element. A tool assembly (40) includes a base plate comprising positioning and centering units (46, 47) on another element with respect to a tapping (35). An electro erosion destruction electrode (51) of the barrel is provided with formation units forming a connection tongue in the barrel. Destruction units destruct a portion of nets (31). An extraction tool extracts the nets from the tapping by the anti-clockwise rotation of the tool. An independent claim is also included for a method for underwater and remote withdrawal of a seized screw to fix a guide tube on an upper plate of upper internal equipments of a nuclear reactor.